1.
a) 9
b)11 la puterea 3
c)
[tex] \sqrt{81 + 144} = \sqrt{225} = 15[/tex]
2.
a=(2+4+6+....+100)-50
a=2(1+2+3+....+50)-50
a=2*50*51:2-50
a=50*51-50
a=2550-50
a=2500
Radical din 2500 =50
=>2500 este patrat perfect
3.
31
4.
[tex] \sqrt{3 \times 6 + 7} - 8 \sqrt{ \frac{25}{100} } + \sqrt{400 - 256} = \\ \sqrt{18 + 7} - 8 \times \frac{5}{10} + \sqrt{144 } = \\ \sqrt{25} - 4 + 12 = \\ 5 - 4 + 12 = \\ 1 + 12 = 13[/tex]